As we get older, we realize how precious our memories are. Fortunately, new research suggests one way to preserve them is to get a good night’s sleep.
A study published in the Journal of Sleep Research in 2014 discovered that those who have less deep sleep (known as slow-wave sleep) also have a decrease in their episodic memory — the memories of what has happened to you.
Long Sleep May Not Be Good Sleep
Just because you’re in bed for the recommended seven to nine hours per night does not mean you are getting optimal sleep. All sleep disorders, including sleep apnea, restless leg syndrome, insomnia and excessive daytime sleep, interrupt your nocturnal sleep. So does noise, the wrong temperature, getting up at night to use the bathroom and having pets in your bedroom.
(MORE: 6 Habits That Ruin a Good Night's Sleep)
“When your sleep is disrupted, it isn’t effective enough to carry out its restorative duties,” says Matthew Thimgan, assistant professor of biological sciences at Missouri University of Science and Technology in Rolla, Mo.
Sleep Apnea and Memory
People with severe sleep apnea never get into the deeper stages of sleep. Because they have to keep waking up to breathe, they don’t get the optimal amount of Stage 2, 3 or 4 sleep, Thimgan says.
Those with sleep apnea get some REM (Rapid Eye Movement) sleep, but it is disrupted and can’t carry out its restorative duties. REM, which comes after Stage 4, provides energy and prepares you to do your best the next day.
“Recently, this has been shown to affect spatial memory,” says Thimgan, who performs sleep research on fruit flies. Spatial memory is the ability to remember your environment. It’s responsible for you being able to do things like navigate the rooms in your house, find your way home and remember where you put your keys.
(MORE: Why Are You Tired All the Time?)
Because of the sleep disruptions, people with sleep apnea are also at a higher risk of dementia or cognitive impairment, says Sonia Ancoli-Israel, director of education at the University of California, San Diego, Sleep Medicine Center.
Sleep, Memory and Aging
Another study, published in the Nature Neuroscience journal in 2013, showed that the quality of sleep affects the ability to retain memories.
A team of University of California at Berkeley researchers discovered a pathway that helps explain the connection between brain deterioration, sleep disruption and memory loss as we age. The study concluded that sleep disruption in older people is a contributing factor to age-related cognitive decline in later life.
The most common sleep complaint of older adults is waking too early and not being able to go back to sleep, Ancoli-Israel says.
Nocturia, or getting up at night because you have to urinate, isn’t serious unless it happens two or more times a night, Ancoli-Israel says, or you can’t fall back to sleep. That is an indication that it could be caused by health problems, including congestive heart failure and sleep apnea.
(MORE: What a Sudden Memory Loss Can Really Mean)
Dr. Sandra Block, a board-certified neurologist and sleep medicine specialist in Williamsville, N.Y., recommends limiting the bedroom to sleep and sex only. Don’t read for hours or pay bills in bed. Your brain gets confused as to what it should be doing. Turn the clock around so you can’t see it and settle into a zone of timelessness, she says.
5 Tips on Getting Better Sleep
Natalie Dautovich, the National Sleep Foundation’s environmental scholar and assistant professor of the Department of Psychology at the University of Alabama in Tuscaloosa, provides five more recommendations:
1. Begin by keeping a sleep journal. That way, you can see patterns and you have something to take to your doctor if necessary. Use this one: sleepfoundation.org/sleep-diary/SleepDiaryv6.pdf or make your own.
2. Clear clutter from your bedroom. Do this by making your bed every day and by not leaving laundry to be folded on the bed. Many people say they sleep better in hotels where they don’t experience any negative cues. Try making your bedroom like a hotel room.
3. Make a written list of what you need to do the night before so you don’t lie in bed and ruminate on upcoming activities.
4. Use blackout curtains or shades to darken the room. Darkness signals your brain that it’s time to sleep.
5. Set the bedroom thermometer to 60 to 67 degrees. When your core body temperature cools, that also signals sleep.
“Aging does not have to be associated with poorer sleep. That’s a myth,” Dautovich says. “You can still have good sleep.” In fact, healthy, active older adults are excellent candidates to get quality sleep. If you aren’t sleeping well, see your doctor.
Heather Larson is a freelancer who often covers health. She has written for Next Avenue, Better Homes and Gardens and Grandparents.com.